Authenticate ad pod manifest requests

For server guided ad insertion, your app makes an ad pod manifest request. For more information, see Generate the ad pod manifest URL.

This page covers authenticating pod manifest requests using Hash-Based Message Authentication Code (HMAC) tokens.

Before you begin

Before you continue, do the following:

Complete the prerequisites.
Ensure you've enabled the Pod resource authentication keys in your livestream event in your Google Ad Manager Account.

Generate an HMAC token

To generate a token, do the following:

Collect the path and query parameters (except auth-token) populated for your pod manifest request. For a full list, see Method: HLS pod manifest or Method: DASH pod manifest.
Combine your parameter key and value strings. You must sort the parameters alphabetically and separate the parameters with the tilde ~ character, for example:
```
ad_break_id=AD_BREAK_ID~custom_asset_key=CUSTOM_ASSET_KEY~exp=EXPIRATION~network_code=NETWORK_CODE~pd=POD_DURATION
```
Calculate a SHA-256 hash of the token string using your DAI authentication key.
Format the hash output in hexadecimal.
To sign the token string, append the signature at the end of the parameters you gathered earlier:
```
ad_break_id=...~hmac=HMAC_SIGNATURE`
```
Replace the HMAC_SIGNATURE with the signature you generated by hashing the token string using your DAI authentication key.
To pass the signed token string safely, apply URL-encoding to the signed token string.

The following example generates the URL-encoded value of a signed token string:

HLS

# Add 60 seconds to the current time
future_epoch=$((EPOCHSECONDS + 60))

echo "Current: $EPOCHSECONDS"
echo "Future: $future_epoch"
# Current: 1774464277
# Future: 1774464337

# Sample DAI pod resource authentication key
key="EB089..."

# Sort parameters in the token string
token="ad_break_id=ab-001~custom_asset_key=hls-pod-serving-manifest-auth-stream-pod~exp=1774464337~network_code=21775744923~pd=30000"

# Generate the token's signature.
echo -n $token | openssl dgst -sha256 -mac HMAC -macopt key:$key

# SHA2-256(stdin)= 68ce65522e0b5f0b4e9a842a0a300e5cba8d14502268b18f66619abcc4dc016e

# Sign the token: ad_break_id=ab-001~custom_asset_key=hls-pod-serving-manifest-auth-stream-pod~exp=1774464337~network_code=21775744923~pd=30000~hmac=68ce65522e0b5f0b4e9a842a0a300e5cba8d14502268b18f66619abcc4dc016e

# Encode the token:
ad_break_id%3Dab-001~custom_asset_key%3Dhls-pod-serving-manifest-auth-stream-pod~exp%3D1774464337~network_code%3D21775744923~pd%3D30000~hmac%3D68ce65522e0b5f0b4e9a842a0a300e5cba8d14502268b18f66619abcc4dc016e

DASH

# Add 60 seconds to the current time
future_epoch=$((EPOCHSECONDS + 60))

echo "Current: $EPOCHSECONDS"
echo "Future: $future_epoch"
# Current: 1774464770
# Future: 1774464830

# Sample DAI pod resource authentication key
key="EB08..."

# Assemble parameters in the token string
token="ad_break_id=ab-001~custom_asset_key=dash-pod-serving-manifest-auth-stream-pod~exp=1774464830~network_code=21775744923~pd=30000"

# Generate the token's signature.
echo -n $token | openssl dgst -sha256 -mac HMAC -macopt key:$key

# SHA2-256(stdin)= 51ce9544b2f04a27d5a818bd982c262f97b7bc64d9e8ea07d13ae73e04062614

# Sign the token: ad_break_id=ab-001~custom_asset_key=dash-pod-serving-manifest-auth-stream-pod~exp=1774464830~network_code=21775744923~pd=30000~hmac=51ce9544b2f04a27d5a818bd982c262f97b7bc64d9e8ea07d13ae73e04062614

# Encode the token: ad_break_id%3Dab-001~custom_asset_key%3Ddash-pod-serving-manifest-auth-stream-pod~exp%3D1774464830~network_code%3D21775744923~pd%3D30000~hmac%3D51ce9544b2f04a27d5a818bd982c262f97b7bc64d9e8ea07d13ae73e04062614

Authenticate a pod manifest request

To authenticate your pod manifest requests, use the auth-token query string parameter to pass the URL-encoded signed HMAC token.

HLS

The following example uses an HMAC token to authenticate an HLS pod manifest request:

curl --include "https://dai.google.com/linear/pods/v1/hls/network/21775744923/custom_asset/hls-pod-serving-manifest-auth-stream-pod/ad_break_id/ab-001.m3u8?stream_id=381c29ff-9015-4f9f-8a43-e2e13822473a:ATL&pd=30000&auth-token=ad_break_id%3Dab-001~custom_asset_key%3Dhls-pod-serving-manifest-auth-stream-pod~exp%3D1774464337~network_code%3D21775744923~pd%3D30000~hmac%3D68ce65522e0b5f0b4e9a842a0a300e5cba8d14502268b18f66619abcc4dc016e"

If successful, you see the following response:

...
< HTTP/2 200
< vary: Accept-Encoding
<
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA:TYPE=AUDIO,URI="https://dai.google.com/linear/pods/v1/hls/event/o35L8Xl8TFa2naph5beXsw/ab_break_id/ab-001/profile/fmp4-audio-128kbps.m3u8?pd=30000&stream_id=9331d770-ae82-460a-96d4-b971eb6f8fa0%3ADLS",GROUP-ID="AUDIO",NAME="mp4a.40.2-0",DEFAULT=YES
#EXT-X-STREAM-INF:BANDWIDTH=1268994,RESOLUTION=1280x720,CODECS="avc1.64001e,mp4a.40.2",AUDIO="AUDIO"
https://dai.google.com/linear/pods/v1/hls/event/o35L8Xl8TFa2naph5beXsw/ad_break_id/ab-001/profile/Video-1200k.m3u8?pd=30000&stream_id=9331d770-ae82-460a-96d4-b971eb6f8fa0%3ADLS
#EXT-X-STREAM-INF:BANDWIDTH=5114591,RESOLUTION=1280x720,CODECS="avc1.4d401f,mp4a.40.2",AUDIO="AUDIO"
...

To understand the response structure and status codes, refer to Method: HLS pod manifest.

If authentication fails, you see the x-ad-manager-dai-warning:

...
< HTTP/2 200
< x-ad-manager-dai-warning: Unable to create ad break due to Unauthorized error (skipping ad break creation)
....
<
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA:TYPE=AUDIO,URI="https://dai.google.com/linear/pods/v1/hls/event/o35L8Xl8TFa2naph5beXsw/ad_break_id/ab-001/profile/fmp4-audio-128kbps.m3u8?pd=30000&stream_id=381c29ff-9015-4f9f-8a43-e2e13822473a%3AATL",GROUP-ID="AUDIO",NAME="mp4a.40.2-0",DEFAULT=YES
#EXT-X-STREAM-INF:BANDWIDTH=1268994,RESOLUTION=1280x720,CODECS="avc1.64001e,mp4a.40.2",AUDIO="AUDIO"
https://dai.google.com/linear/pods/v1/hls/event/o35L8Xl8TFa2naph5beXsw/ad_break_id/ab-001/profile/Video-1200k.m3u8?pd=30000&stream_id=381c29ff-9015-4f9f-8a43-e2e13822473a%3AATL
#EXT-X-STREAM-INF:BANDWIDTH=5114591,RESOLUTION=1280x720,CODECS="avc1.4d401f,mp4a.40.2",AUDIO="AUDIO"
https://dai.google.com/linear/pods/v1/hls/event/o35L8Xl8TFa2naph5beXsw/ad_break_id/ab-001/profile/media-ts-4628000bps.m3u8?pd=30000&stream_id=381c29ff-9015-4f9f-8a43-e2e13822473a%3AATL

DASH

The following example uses an HMAC token to authenticate a DASH pod manifest request:

curl --include "https://dai.google.com/linear/pods/v1/dash/network/21775744923/custom_asset/dash-pod-serving-manifest-auth-stream-pod/stream/310b1882-4a62-436a-99b1-ca56435b48f6:TUL/ad_break_id/ab-001/manifest.mpd?pd=30000&auth-token=ad_break_id%3Dab-001~custom_asset_key%3Ddash-pod-serving-manifest-auth-stream-pod~exp%3D1774464830~network_code%3D21775744923~pd%3D30000~hmac%3D51ce9544b2f04a27d5a818bd982c262f97b7bc64d9e8ea07d13ae73e04062614"

If successful, you see the following response:

...
HTTP/2 200
<?xml version="1.0" encoding="UTF-8"?>
<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:_XMLSchema-instance="http://www.w3.org/2001/XMLSchema-instance" _XMLSchema-instance:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" id="201" profiles="urn:hbbtv:dash:profile:isoff-live:2012" type="static" mediaPresentationDuration="PT30S" minBufferTime="PT2S">
<Period id="1" duration="PT30S">
  <BaseURL>https://dai.google.com/linear/pods/v1/seg/event/310b1882-4a62-436a-99b1-ca56435b48f6:TUL/ad_break_id/ab-001/profile/</BaseURL>
  <SegmentTemplate startNumber="0" media="$RepresentationID$/$Number$.mp4?stream_id=310b1882-4a62-436a-99b1-ca56435b48f6:TUL&amp;sd=5000&amp;pd=30000" initialization="$RepresentationID$/init.mp4?stream_id=310b1882-4a62-436a-99b1-ca56435b48f6:TUL&amp;pd=30000">
    <SegmentTimeline>
      <S d="5" r="5"/>
    </SegmentTimeline>
  </SegmentTemplate>
  <AdaptationSet mimeType="video/mp4" scanType="progressive" contentType="video">
    <Role schemeIdUri="urn:mpeg:dash:role:2011" value="main"/>
    <Representation width="1280" height="720" frameRate="25" codecs="avc1.64001f" id="Video-1200k" bandwidth="1300000">
      <InbandEventStream schemeIdUri="https://developer.apple.com/streaming/emsg-id3"/>
    </Representation>
  </AdaptationSet>
  <AdaptationSet mimeType="audio/mp4" scanType="progressive" contentType="audio">
    <Role schemeIdUri="urn:mpeg:dash:role:2011" value="main"/>
    <Representation audioSamplingRate="48000" codecs="mp4a.40.2" id="fmp4-audio-128kbps" bandwidth="128000">
      <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>
    </Representation>
  </AdaptationSet>
</Period>
</MPD>

To understand the response structure and status codes, refer to Method: DASH pod manifest.

If authentication fails, you see the x-ad-manager-dai-warning:

...
< HTTP/2 200
< access-control-allow-headers: Authorization
< x-ad-manager-dai-warning: Unable to create ad break due to Unauthorized error (skipping ad break creation)
<
<?xml version="1.0" encoding="UTF-8"?>
<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:_XMLSchema-instance="http://www.w3.org/2001/XMLSchema-instance" _XMLSchema-instance:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" id="201" profiles="urn:hbbtv:dash:profile:isoff-live:2012" type="static" mediaPresentationDuration="PT30S" minBufferTime="PT2S">
<Period id="1" duration="PT30S">
<BaseURL>https://dai.google.com/linear/pods/v1/seg/event/310b1882-4a62-436a-99b1-ca56435b48f6:TUL/ad_break_id/ab-001/profile/</BaseURL>
<SegmentTemplate startNumber="0" media="$RepresentationID$/$Number$.mp4?stream_id=310b1882-4a62-436a-99b1-ca56435b48f6:TUL&amp;sd=5000&amp;pd=30000" initialization="$RepresentationID$/init.mp4?stream_id=310b1882-4a62-436a-99b1-ca56435b48f6:TUL&amp;pd=30000">
<SegmentTimeline>
<S d="5" r="5"/>
</SegmentTimeline>
</SegmentTemplate>
<AdaptationSet mimeType="video/mp4" scanType="progressive" contentType="video">
<Role schemeIdUri="urn:mpeg:dash:role:2011" value="main"/>
<Representation width="1280" height="720" frameRate="25" codecs="avc1.64001f" id="Video-1200k" bandwidth="1300000">
<InbandEventStream schemeIdUri="https://developer.apple.com/streaming/emsg-id3"/>
</Representation>
</AdaptationSet>
<AdaptationSet mimeType="audio/mp4" scanType="progressive" contentType="audio">
<Role schemeIdUri="urn:mpeg:dash:role:2011" value="main"/>
<Representation audioSamplingRate="48000" codecs="mp4a.40.2" id="fmp4-audio-128kbps" bandwidth="128000">
<AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>
</Representation>
</AdaptationSet>
</Period>
</MPD>

Authenticate ad pod manifest requests Stay organized with collections Save and categorize content based on your preferences.

Before you begin

Generate an HMAC token

HLS

DASH

Authenticate a pod manifest request

HLS

DASH

Authenticate ad pod manifest requests